public class MyUtil5317{
    public static String percentage2fivegrade(int grade){
        if (grade < 60 && grade >= 0 )
            return "不及格";
        else if (grade < 70 && grade >= 0 )
            return "及格";
        else if (grade < 80 && grade >= 0 )
            return "中等";
        else if (grade < 90 && grade >= 0 )
            return "良好";
        else if (grade <= 100 && grade >= 0 )
            return "优秀";
        else
            return "错误";
    }
}